Liam Neeson stood up after the first group reading of the script for The Grey and told the young actors in the cast that the only way this movie could be made was for all of them to pull together.
That's because the story of plane crash survivors who battle hungry wolves was filmed on a mountain in Canada where the temperatures fell to minus 40 degrees and there were whiteout conditions.
Although the actors say Neeson didn't need any help and became an inspiration to them all, the filming was tough on the veteran actor.
Physically, he had to deal with the snow and cold. Emotionally, his character is on a spiral after the death of his wife. Neeson's wife, actress Natasha Richardson, suffered a fatal head injury in a skiing accident in 2009.
On the emotional toll, Neeson only will say that he had a place to go to find the feelings to play the scenes, but he didn't dwell on it during the filming. He prefers to talk about the physical demands.
"The first day of shooting I am wearing only a sweater and I remember thinking we are never going to finish this film," Neeson says.
Even when the wind wasn't howling and the temperature crawled above zero, the actors still had to contend with the waist-deep snow. Neeson called walking 25 yards (22.86 metres) in the drifts as difficult as a two-hour workout.
Because scenes had to be shot multiple times, the actors could not walk through their own footsteps. They would move a few yards to the left or right and struggle again through the snow banks.
"There was very little acting done. It was just 'I have to get there with some sort of pace'," Neeson says. "The physical aspect for all of us was very, very tough."
Even getting ready for work was difficult because of all the layers the actors had to wear to try to stay warm. Neeson jokes he was wearing so much clothing that he felt like the Michelin Man.
Working in the snow meant the actors burned calories at a fast rate. During every break, they had to eat to maintain their energy.
It wasn't just the actors who had to deal with the bitter cold. Director Joe Carnahan decided to shoot the film digitally to eliminate as many moving parts in equipment as possible. But that didn't stop everything from freezing and locking up. Plans for several overhead shots had to be axed when the crane froze solid after the first shot.
It was an extremely demanding shoot. And it was something in those demands that lured Neeson to the film.
This kind of action film has become the norm for Neeson in recent years. Although he's going to film Taken 2, Neeson, who turns 60 later this year, says he's only got another year of making action movies left in him because his "knees are complaining daily".
Of course, if a great script comes along, all bets are off.